Well, regulation can be in any form eg :
1. Allowing people to own and trade Bitcoin, but not using it as a currency.
2. Banning merchants and vendors from accepting Bitcoin as a payment method.
3. Implementing very strict AML/KYC regulations, to slow it's adoption or to restrict it's use. {High licensing fee's would exclude small operators}
New York4. They can ban everything {trade & currency}
5. They can over TAX it, to kill it's usefulness. {Some countries do the opposite and exempt it from VAT}
6. They could place limits on the amount of coins that can be traded or owned.
Governments can basically do whatever they want to do. We are the puppets and they are the puppet masters... We can only make sure, we vote for the people we want to represent us there. In some countries this is
not even a option. Obama just told the African countries, that democracy is not just a free voting system... It's also the freedom to speak and to voice your needs and concerns as a citizen.